Terminal services provide techniques for allowing access to applications and data stored on servers. User input is sent over a network connection to a server and audio and graphics are sent from the server to a client. Over the years different techniques have been developed to remote graphics such as command level remoting and bitmap level remoting.
Bitmap level remoting is generally considered to be the easier of the two techniques to implement. In bitmap remoting, the graphics processing is performed on the terminal server and the final image, e.g., an array of pixel values that forms a bitmap, is compressed and sent over the network to the client. This technique requires a server that has enough computational power to render images for one or more clients.
Command level remoting on the other hand offloads the graphics processing to the client. Primitives, e.g., vertices that can be processed by a driver and executed by a graphics processor, can be captured and sent to the client. This reduces the processing power required to remote graphics, however more bandwidth is needed to transport the data representing the 3D graphics primitives than using bitmap remoting. Accordingly, techniques for reducing the bandwidth required to effectuate command level remoting are desirable.